The manufacturers of Boris Johnson's multimillion pound new London bus threatened to prevent publication of a book criticising the design and construction of the vehicles.
Wrightbus complained that photos in the book of loose ceiling panels and broken light fittings, as well as criticisms of the bus's green credentials were "defamatory" and risked "serious reputational damage" to the company.
They ordered publishers Capital Transport Publishing to remove the excerpts from their book Boris's Bus or face "injunctive proceedings to prevent publication of the book."
Solicitors acting on behalf of Wright Bus complained that the book "suggests that there are problems with the design and manufacture of the vehicles."
They took particular issue with one excerpt in the book claiming the buses were "reported to be falling short in their fuel consumption and emission figures, in some cases worryingly."
The excerpts are believed to have been kept in the book, which was written by a number of authors including transport commentator and mayoral hopeful Christian Wolmar.
Transport for London have denied any involvement in trying to prevent the publication of the book.
"At no point has TfL sought to stop the publication of Capital Transport’s book," a spokesperson said.
"Some time ago we were approached by an author, who was keen to write a book on the New Bus for London project, whom we introduced to specialist publisher, Capital Transport. We also gave the author access to official documents, photographs and designs as well as interviews with officials and other parties involved in the project.
"Unfortunately there were disagreements between the author and publisher and their partnership was terminated. The dissolution of the agreement involved correspondence between solicitors."
Boris Johnson first promised to introduce a new Routemaster-style bus in his first Mayoral election campaign in 2008.
However, the buses have been beset with problems, including breakdowns and oppressively hot conditions.
Earlier this month Johnson joked to journalists that conditions on the buses were akin to a "bikram yoga style sauna".
At least four people have so far also been taken to hospital after falling from the open rear platforms of the bus, according to TfL figures.